Method for applying flowable materials

ABSTRACT

Methods and apparatuses are disclosed for applying melt flowable materials to components of articles of manufacture. The methods and apparatuses disclosed herein are concerned with formation of appropriate flowable materials, control over the manner in which the flowable materials are applied, treatment of the components prior to application of the flowable materials and the like. Moreover, the apparatuses and methods may be particularly suited for applying flowable materials to surfaces and components found in automotive, aerospace, and marine vehicles.

This application is a continuation of application Ser. No. 10/342,025filed on Jan. 14, 2003, now U.S. Pat. No. 7,043,815 which is anon-provisional of application No. 60/351,967 filed on Jan. 25, 2002.

CLAIM OF BENEFIT OF FILING DATE

The present application claims the benefit of the filing date of U.S.Provisional Patent Application Ser. No. 60/351,967 (filed Jan. 25,2002), hereby incorporated by reference.

TECHNICAL FIELD

The present invention generally relates to methods and apparatuses forapplying flowable materials to articles of manufacture. Moreparticularly, the present invention relates to methods and apparatusesfor applying melt flowable materials such as adhesive materials, sealantmaterials, expandable materials, weldable materials, structuralmaterials, paintable materials or the like to components of automotivevehicles.

BACKGROUND OF THE INVENTION

Sealants, adhesives and other flowable or moldable materials are oftenused on various components of a variety of articles of manufacture. Suchflowable materials, for example, are applied to several components of anautomotive vehicle for purposes such as increasing the structuralintegrity of the vehicle, sealing, attaching components of the vehicletogether, or improving vehicle noise, vibration or harshness (NVH)characteristics.

Application of the flowable materials to the various components cancreate a variety of challenges. There may be challenges presented informing flowable materials with desired properties. For instance, theflowable materials may need to be formed with chemical properties,physical properties or both, which are compatible with the components towhich the flowable materials are applied thereby allowing the flowablematerials to adhere or otherwise interact with the components. There maybe further challenges presented in designing and manufacturing effectiveapparatuses for applying the flowable materials to different components.For instance, challenges may be presented for forming apparatuses thatcan properly control the rates of creation and the rates of output ofthe flowable materials. There may be still further challenges presentedby the various design aspects of the components to which the flowablematerials are applied. For instance, the geometry of the components, theprocessing of the components and other similar design aspects canpresent a myriad of challenges to application of the flowable materials.

A number of methods found in the prior art relate to so-called“pumpable” products that are fluidic materials applied to selectedportions of a vehicle during the assembly process. Although thesemethods may be highly advantageous in some circumstances andapplications, the use of pumpable materials and equipment often tend tocreate additional maintenance and clean-up requirements in themanufacturing facility as well as increased labor demand. Certainaspects of the present invention serve to eliminate the need forpumpable products and methods by providing a method, process, andapparatus for the extrusion-in-place or dispensing of flowable materialsdirectly to a selected surface or location through improved extrusiontechniques, which can be employed for applying a variety ofthermoplastic and thermosettable materials.

Accordingly, the methods and apparatuses disclosed in the presentinvention overcome the drawbacks and disadvantages of the prior art byeconomically and effectively extruding or otherwise dispensing flowablematerials to components of articles of manufacture.

SUMMARY OF THE INVENTION

The present invention broadly involves methods and apparatuses forapplying flowable materials onto components of articles of manufacture.In particular preferred embodiments, the invention involves preciselyextruding a highly viscous flowable material onto one or morepredetermined locations of one or more components of an automotivevehicle.

The flowable materials being applied according to the present inventionmay be adhesive materials, sealant materials, expandable materials,structural materials, weldable materials, weld-through materials,paintable materials or other suitable flowable materials. In one highlypreferred embodiment, the flowable materials may be treated or otherwiseprocessed for the application of additional materials which facilitateand allow the formation of a class A painted surface finish, or otherclass of painted or treated surface, upon the flowable material. Inother embodiments, the flowable materials may be electricallyconductive, insulative, magnetic, transparent or possess anotheradvantageous property along some or all of its length.

Preferably, the flowable materials are applied as one or more blends ina first physical state (e.g., unfoamed, having a particular sectionalprofile, uncured, or otherwise) and are thereafter exposed to a stimulussuch as heat, a chemical or another suitable stimulus to induce oractivate the flowable materials to transform (reversibly orirreversibly) to a second physical state (e.g., foamed, to a differentsectional profile, cured or otherwise). Moreover, the flowable materialsmay intrinsically exhibit various desirable properties such as soundabsorption, vibration absorption, corrosion resistance, adhesivity,sealing properties, strength, stiffness and the like which may enhancerespective properties of components that receive the materials.Alternatively, the flowable materials when applied, produce acombination with the underlying component that is enhanced in one oremore relevant property.

The present invention is further characterized by the use of equipmentand methods, such as improved extrusion methods, designs, and equipment,which apply material directly onto the receiving part to form anassembly that can be further handled and incorporated in the assemblyprocess. It is contemplated that the materials to be utilized in thepresent invention will generally be flowable materials, such asthermoplastic or thermosettable materials, typically encountered inmanufacturing operations, such as the manufacturing of automotive,aerospace, marine and other vehicles as well as appliances, motor drivendevices, and articles of furniture.

One preferred apparatus of the present invention typically includes anapplicator for reproducibly dispensing the flowable materials onto asurface. In one embodiment, the apparatus includes an extruder fordispensing the flowable material through a die. In other embodiments,the apparatus may include mechanisms for moving components relative toan applicator (e.g., a die) of the apparatus, mechanisms for moving theapplicator relative to the components or a combination thereof. Forexample, the extrusion apparatus and mechanisms of the present inventionmay utilize at least one roller bearing capable of double actionmovement to push and roll the chosen material. More particularly, thepresent invention may include extrusion devices having at least onedrive screw which interacts and responds to reaction force to attenuateconsistency, set back, ramping, and control of response time. In thisregard, the present invention may utilize a servo driven positioncontrolled system to drive the screw of the extruder and control itsoperations and response time, which can be as low as about 0.1 second.In this aspect of the present invention, the servo driven positioncontrolled system may further comprise a servo loop, which receivesfeedback from an encoder, a servo valve, which provides the positioncontrol, and computer software to facilitate communication of the servosystem and direct the system to function to the preselected responsetime. In still other embodiments, the present invention may incorporatean apparatus for the precision control system for the dispensing andapplication of flowable materials.

Among the methods of the present invention are methods for forming theflowable materials, methods for applying the flowable materials, methodsfor treating the surfaces of the components to which the flowablematerials are applied, and combinations of such methods.

The components that receive a flowable materials preferably provide asurface suitable for receipt of the flowable material. In oneembodiment, the surface of a component is configured to include astructure for increasing surface area for receiving the flowablematerials, such as a channel, a rib, or otherwise. In anotherembodiment, the surfaces of the components may be treated (e.g.,pretreated, post-treated or otherwise) to enhance adhesion of theflowable materials to its application surface. According to anotheraspect of the invention, flowable materials are applied to componentsthat were previously unsuitable for receiving the flowable materialsbecause of the nature or properties of the flowable materials, thecomponents or both.

BRIEF DESCRIPTION OF THE DRAWINGS

These, and further aspects or embodiments of the invention will be madeclear or will be become apparent during the course of the followingdescription of a preferred embodiment of the present invention. In thedrawings, which form an integral part of the specification and are to beread in conjunction therewith, and in which like reference numerals areemployed to designate identical parts in the various views:

FIG. 1 is a perspective view of an apparatus having an illustrativeportable extruder shown mounted on the end of a robotic arm, depictinguse of the apparatus to apply extruded materials to parts on an off-linebasis according to one aspect of the present invention;

FIG. 2 is a sectional view of the portable extruder, taking along theline 2-2 in FIG. 1;

FIG. 3 is an operational diagrammatic view of the portable extrudershown in FIG. 1;

FIG. 4 is a view of the portable extruder of FIG. 1, but shown inrelationship to an assembly line for manufacturing automobiles;

FIG. 5 is an enlarged, perspective view of a portion of a vehicle bodyand the extruder shown in FIG. 4;

FIG. 6 is a cross-sectional view taken along the line 6-6 in FIG. 5;

FIGS. 7 a and 7 b are views similar to FIG. 6 but showing a roof panelhaving been installed, and depicting the position of the extrudedsealant bead respectively before and after expansion thereof;

FIG. 8 is a fragmentary, cross-sectional view of an alternate form of anozzle for use with the extruder of FIG. 1;

FIG. 9 is a perspective view of an extruder according to the presentinvention, depicting an alternate form of a material supply system;

FIG. 10 is an enlarged, cross-sectional view of the batch hopper andsupply feed tube of the system shown in FIG. 9, immediately after abatch has been dispensed;

FIG. 11 is a perspective view of an alternate form of the extruder ofthe present invention, shown in relationship to a conveyor line; and

FIG. 12 is a fragmentary rear view of the extruder of FIG. 11.

FIG. 13 is a block diagram of an automated system for trackingmaterials.

FIG. 14 is an overhead view of a system and apparatus for dispensingflowable materials onto panels of automotive vehicles.

FIG. 15 is close-up of another sectional view of the portable extruderincluding two thrust bearings.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present invention involves applying flowable material to variouscomponents of articles of manufacture such as automotive vehicles. Thedescription of this invention first discusses the potential flowablematerials that can be applied according to the methods and using theapparatuses of the invention. Thereafter, the methods and apparatusesthat may be used for applying the flowable materials are discussed.Lastly, the components of the articles of manufacture that receive theflowable materials and the manner in which the flowable materials areapplied are discussed.

Flowable Materials

The flowable materials of the present invention can be chosen from avariety of different materials. In certain cases, the flowable materialsmay be conventional, but may be applied according to novel methods orusing novel apparatuses or both. In other cases, the flowable materialsmay be conventional or known, however, the component to which theflowable materials are applied may be novel. In still other embodiments,the flowable materials themselves may be novel. The discussion below ismeant to introduce the flowable materials generally according to theirchemical makeup and in terms of properties exhibited by the flowablematerials, for assisting a person of skill in art in choosing amaterial, which typically needs to be selected or tailored for aspecific desired application.

According to one embodiment of the invention, the flowable materials maybe heat activated. A preferred heat activated material is an expandableor other flowable polymeric formulation or composition, and preferablyone that is activated to foam, flow or otherwise change states whenexposed to the heating operation of a typical automotive paintingoperation such as during a primer or paint drying step. A particularlypreferred material is an active polymer formulated in pellet form witheach pellet typically 1-20 mm in diameter and generally, but notnecessarily, configured in a geometric or polygonal shape, such as asphere, to facilitate the flow of such pellets through an applicatorsuch as an extruder. One preferred material is formed of an olefinicpolymer-based foam, and more particularly an ethylene based polymer. Forexample, without limitation, the polymeric foam may be based on ethylenecopolymers or terpolymers that may possess an alpha-olefin. As acopolymer or terpolymer, the polymer is composed of two or threedifferent monomers, i.e., small molecules with high chemical reactivitythat are capable of linking up with similar molecules. Examples ofparticularly preferred polymers include ethylene vinyl acetate, EPDM, ora mixture thereof. Without limitation, other examples of preferred foamformulation that are commercially available include polymer-basedmaterial commercially available from L&L Products, Inc. of Romeo, Mich.,under the designations as L-2105, L-2100, L-7005 or L-2018, L-7100,L-7101, L-7102, L-7700, L-2410, L-2411, L-2412, L-4201, L-4141, etc. andmay comprise either open or closed cell polymeric base material. Suchmaterials may exhibit properties including sound absorption, vibrationabsorption, sealing ability, corrosion resistance and the like.

The material may also be a heat-activated epoxy-based resin havingfoamable characteristics upon activation through the use of heattypically encountered in an e-coat or other automotive paint ovenoperation. As the expandable material is heated, it expands,cross-links, and structurally bonds to adjacent surfaces. An example ofa preferred formulation is an epoxy-based material that may includepolymer modificis such as an ethylene copolymer or terpolymer that iscommercially available from L&L Products, Inc. of Romeo, Mich., underthe designations that include L-5204, L-5206, L-5207, L-5208, L-5222 orcombinations thereof. Such materials may exhibit properties includingrelatively high strength and stiffness, promote adhesion, rigidity, andimpart other valuable physical and chemical characteristics andproperties.

When acoustical damping properties are desired, it is contemplated thatthe present invention may utilize a foamable material formulated toassist in the reduction of vibration and noise after activation. In thisregard, reinforced and vibrationally damped components can haveincreased stiffness which will reduce natural frequencies, that resonatethrough the automotive chassis thereby reducing transmission, blockingor absorbing noise through the use of the conjunctive acoustic product.By increasing the stiffness and rigidity of the components of a vehicle,the amplitude and frequency of the overall noise, vibration or both thatoccurs from the operation of the vehicle and is transmitted through thevehicle can be reduced.

In addition to the use of an acoustically damping material, the presentinvention could comprise the use of a combination of an acousticallydamping material and a structurally reinforcing expandable materialalong different portions or zones of the member depending upon therequirements of the desired application. Use of acoustic expandablematerials in conjunction with structural material may provide additionalstructural improvement but primarily would be incorporated to improveNVH characteristics.

A number of other suitable epoxy-based materials are known in the artand may also be used. One such foam preferably includes a polymeric basematerial, such as an ethylene-based polymer which, when compounded withappropriate ingredients (typically a blowing and curing agent), expandsand cures in a reliable and predicable manner upon the application ofheat or the occurrence of a particular ambient condition. From achemical standpoint for a thermally activated material, the foam isusually initially processed as a flowable thermoplastic material beforecuring. It will cross-link upon curing, which makes the materialresistant of further flow or change of final shape.

The flowable material can be formed of other materials (e.g., foamsregarded in the art as structural foams) provided that the materialselected is heat-activated or otherwise activated by an ambientcondition (e.g. moisture, pressure, time or the like) and cures in apredictable and reliable manner under appropriate conditions for theselected application. One such material is the polymeric based resindisclosed in commonly owned, co-pending U.S. patent application Ser. No.09/268,810 (filed Mar. 8, 1999), the teachings of which are incorporatedherein by reference.

Some other possible materials include, but are not limited to,polyolefin materials, copolymers and terpolymers with at least onemonomer type an alpha-olefin, phenol/formaldehyde materials, phenoxymaterials, and polyurethane. See also, U.S. Pat. Nos. 5,266,133;5,766,719; 5,755,486; 5,575,526; 5,932,680; and WO 00/27920 (PCT/US99/24795) (all of which are expressly incorporated by reference).Examples of suitable melt flow materials include, without limitation,formulations found in a commonly owned co-pending applications for aPaintable Seal System filed Aug. 7, 2000, and a Paintable Material filedAug. 24, 2001, both hereby incorporated by reference. Still othermaterials and methods are disclosed in co-pending U.S. applicationtitled “Sound Absorption System for Automotive Vehicles”, Ser. No.09/631,211, filed Aug. 3, 2000.

In general, some desired characteristics of the resulting materialinclude relatively low glass transition point, and good corrosionresistance properties. In this manner, the material does not generallyinterfere with the materials systems employed by automobilemanufacturers. Moreover, it will withstand the processing conditionstypically encountered in the manufacture of a vehicle, such as thee-coat priming, cleaning and degreasing and other coating processes, aswell as the painting operations encountered in final vehicle assembly.

In this regard, in applications where a heat activated, thermallyexpanding material is employed, a consideration involved with theselection and formulation of the material is the temperature at which amaterial reaction or expansion, and possibly curing, will take place.For instance, in most applications, it is undesirable for the materialto be reactive at room temperature or otherwise at the ambienttemperature in a production line environment since, in one embodiment,the material is extruded onto the intrusion device by a supplier andthen shipped to the vehicle manufacturer as an integrated product. Moretypically, the material becomes reactive at higher processingtemperatures, such as those encountered in an automobile assembly plant,when the material is processed along with the vehicle components atelevated temperatures or at higher applied energy levels, e.g., duringe-coat preparation steps and other paint cycles. While temperaturesencountered in an automobile e-coat operation may be in the range ofabout 145° C. to about 210° C. (about 300° F. to 400° F.), primer,filler and paint shop applications are commonly about 100° C. (about200° F.) or higher. The material is thus operative throughout theseranges. If needed, blowing agent activators can be incorporated into thecomposition to cause expansion at different temperatures outside theabove ranges.

Generally, suitable expandable flowable materials have a range ofvolumetric expansion from approximately 0 to over 2000 percent. Thelevel of expansion of the vibration reduction material 20 may beincreased to as high as 1500 percent or more. In certain embodiments,the material may be hyper-expandable materials that expand more than1500 percent and preferably over about 2000 percent. The material may beexpandable to a degree (or otherwise situated on a surface) so thatindividual nodes remain separated from one another upon expansion, orthey may contact one another (either leaving interstitial spaces ornot).

In another embodiment, the material may be provided in an encapsulatedor partially encapsulated form, which may comprise a pellet, whichincludes an expandable foamable material, encapsulated or partiallyencapsulated in an adhesive shell. An example of one such system isdisclosed in commonly owned, co-pending U.S. application Ser. No.09/524,298 (“Expandable Pre-Formed Plug”), hereby incorporated byreference.

Moreover, the flowable material may include a melt-flowable materialsuch as that disclosed in U.S. Pat. No. 6,030,701 (expresslyincorporated by reference).

The choice of the flowable material used will be dictated by performancerequirements and economics of the specific application and requirements.Generally speaking, automotive vehicle and other applications mayutilize technology and processes such as those disclosed in U.S. Pat.Nos. 4,922,596, 4,978,562, 5,124,186, and 5,884,960 and commonly owned,co-pending U.S. application Ser. No. 09/502,686 filed Feb. 11, 2000,Ser. No. 09/524,961 filed Mar. 14, 2000, Ser. No. 60/223,667 filed Aug.7, 2000, No. 60/225,126 filed Aug. 14, 2000, Ser. No. 09/676,443 filedSep. 29, 2000, Ser. No. 09/676,335 filed Sep. 29, 2000, Ser. No.09/676,725 filed Sep. 29, 2000, and particularly, Ser. No. 09/459,756filed Dec. 10, 1999, all of which are expressly incorporated byreference.

For application purposes, it is often desirable for the flowablematerials of the present invention to be formulated such that thematerials exhibit desired properties (e.g., tackiness or non-tackiness)at various different processing stages or temperature. Of course, it iscontemplated that such properties or temperatures may be variabledepending upon the application of the flowable materials.

As discussed particularly for automotive operations, it is generallydesirable for flowable materials of the present invention to activateand flow at temperatures experienced during paint cycles. Prior toactivation, however, it is often preferable for the flowable materialsto be exhibit solid and substantially non-tacky characteristics attemperatures near room temperature (e.g., between about 5° C. and about50° C.), while exhibiting characteristics of slight flow and tackinesswithout activation at mid-level temperatures (e.g., between about 50° C.and about 100° C.). Advantageously, these characteristics allow thematerials to be stored, transported and maintained in pellet formwithout substantial adhesion between the pellets. At the same time, thematerials can be heated to mid-level temperatures to allow the materialsto adhere to a substrate during application of the materials as furtherdiscussed below.

For forming a flowable material that exhibits such desiredcharacteristics, a base resin with a narrow molecular weightdistribution is preferably included in the material. The molecularweight distribution is preferably such that 70% of the polymers in thebase resin are within 10,000 atomic mass units (amu) of each other, morepreferably 80 percent of the polymers in the base resin are with 5000amu of each other and even more preferably 90 percent of the polymersare within 1000 amu of each other. Preferably, the base resin comprisesabout 50 to about 100 weight percent of the material or of the polymericconstituents of the material and more preferably about 60 to about 90weight percent of the material or of the polymeric constituents of thematerial.

It is also contemplated that the flowable materials may be formulatedwith one or more components, which assist in adhering the materials to asubstrate upon application thereto. Typically, such components are addedto achieve desirable interaction between the flowable materials andcontaminants (e.g., oil and lubricants), which may be present upon asurface of a substrate to which the flowable material may be applied.

In one embodiment, the flowable material includes one or moresolubilizing agents, which assist the flowable material in solubilizingcontaminants on a substrate surface. Examples of such solubilizingagents include hydrocarbons (e.g, hydrocarbon process oils), pthalateplasticizers, liquid polyolefins or the like. Preferably, when used,such solubilizing agents are between about 1 and about 30 weight percentof the flowable material, more preferably between about 5 and about 20weight percent of the flowable material.

In another embodiment, the flowable material includes one or moreincompatible or low compatibility components, which can displacecontaminants upon application of the flowable material to a substratethereby assisting in adhesion of the flowable material to the substrate.Preferably, such components have relatively low molecular weights (e.g.,less than 1000 g/mole) such that the components tend to migrate out theresin system of the flowable material. Examples of such componentsinclude polybutenes, polybutadienes, various waxes or the like.Preferably, when used, such low compatibility components are about 0.1and about 30 weight percent of the flowable material, more preferablybetween about 2 and about 15 weight percent of the flowable material.

In another embodiment, the flowable material includes one or more polarcomponents, which can aid in adhesion of the flowable material to thesubstrate. Preferably, such components have relatively low meltingpoints (e.g., between about 50° C. and about 100° C.). Examples of suchcomponents include oxidized or otherwise functionalized waxes, epoxyresins or combinations thereof. Preferably, when used, such polarcomponents are about 1 and about 30 weight percent of the flowablematerial, more preferably between about 2 and about 15 weight percent ofthe flowable material.

In still another embodiment, the flowable material includes one or morecomponents such as waxes that are modified with an adhesion promotersuch as an acid anhydride group. Preferably, when used, such modifiedcomponents are about 1 and about 30 weight percent of the flowablematerial, more preferably between about 5 and about 20 weight percent ofthe flowable material.

In yet another embodiment, the flowable material includes atwo-component system wherein a first component interacts with a secondcomponent to increase tack of the flowable material during application.For example, pellets of a relatively lower molecular weight material maybe combined with pellets of a compatible higher molecular weight basepolymer, which, upon mixing and elevation to a mid-range temperature,increase tack due to the compatibility of the two types of pellets. Asanother example, a small amount of pellets of one material may becombined with pellets formed of a second material wherein the firstmaterial has reactive functionality that is activated upon mixing withthe second material for promoting adhesion.

Apparatuses for Application of Flowable Materials

An apparatus for applying flowable materials to components according tothe present invention may be provided in a variety of configurations.The apparatus typically includes at least one applicator having anoutlet through which the flowable materials are passed. The applicatormay comprise molding equipment such as compression or injection moldingequipment, extrusion equipment or other applicator equipment. Theapparatus preferably assists in forming the flowable materials into adesired configuration prior to applying the materials. Additionally, theapparatus may be capable of moving its applicator (e.g., via a singleaxis or multiple axis robot art) to assist the applicator in applyingthe flowable materials to one or more components.

Referring first to FIGS. 1, 2 and 3, there is illustrated an exemplaryembodiment of an apparatus for applying melt flowable materials. Theapparatus generally includes a lightweight, portable material applicatorgenerally indicated by the numeral 20. The applicator for the presentinvention may be an extruder, pressure applicator such as hydraulic,electric or pneumatic applicators or another suitable applicator.

In FIGS. 1 and 3 the applicator 20 is shown as an extruder mounted on arobot mechanism 22. The robot 22 includes a stationarily mounted base 26upon which there is rotatably mounted a turret 24, along with threepivotally connected arms 28, 30 and 32. As illustrated withoutlimitation, the applicator 20 is mounted on the end of the arm 32 andthus has freedom of movement about 6 axes. In alternative embodiments,the applicator 20 may be moveable by a mechanism other than the robot22. For instance, the applicator 20 may be mounted on tracks that permitmovement of the applicator in one or a plurality of axes. In still otheralternative embodiment, the applicator 20 may be stationary.

In FIG. 1, the applicator 20 is operated on an off-line basis to applyextrusions at appropriate locations on parts that may be stationary ormoving, such as to the illustrated roof panels 34 which are mounted onjigs 36 supported on individual tables 38. The extruder 20 is powered bya suitable motor 72 (such as a hydraulic motor), which is coupled with adrive mechanism, such as one including a pair of hydraulic lines 42 to ahydraulic pump 44 and related reservoir tank of hydraulic fluid 46.

The flowable materials may be supplied to the applicator according tovarious protocols. The flowable materials may be pumped to theapplicator in a flowable state. They may be conveyed by a mechanicalconveyor. They may be advanced by a screw. They my be advanced by apiston. Other approaches are also possible. Materials may be fed to theapplicator as a solid and the applicator may process the materials(e.g., with heat, a solvent, a reactant or a combination thereof) toform flowable materials. Additionally, various ingredients may be fed tothe applicator at various locations. For example, an extruder may haveone or a plurality of inlets for receiving various ingredients that areintroduced and mixed within the extruder.

The material may be supplied from nearly any suitable container such asa bin or other container, and the material may be supplied in many formssuch as pellets, granules, particles or the like. Examples of suitablepellet shapes include cylinders, polyhedron, egg-shaped, oblongtrapezoids, rings, cubes, spheres, hemispheres, polyhedrons, prisms,pyramids or other geometric or irregular shapes.

The form in which the material is supplied will typically depend uponthe nature of the material being supplied. Generally, it is preferablethat the pellets include very few, if any, sharp edges. As used hereinedges of the pellets are typically defined by adjoining surfaces of thepellets and the sharpness of those edges is typically defined by theangle at which the surfaces are disposed relative to each other (i.e.,the sharper the edge, the smaller or more acute the angle). In apreferred embodiment, the surfaces forming edges on the pellets aredisposed at greater than about 70°, more preferably greater than about90° and even more preferably greater than about 110°. In a highlypreferred embodiment, the pellets are substantially free of edges, andinclude only curved surfaces, flat surfaces or both.

As an example, without limitation FIG. 1 shows a supply bin 52 mountedupon a table 54 which tilts about a pivot point 56 in response toelevation by a pneumatic cylinder 58. A vacuum pump 48 draws the solidpellets of material from the supply bin 52 through a draw tube 50 to apoint elevated above the applicator 20. The pellets are then gravity fedthrough the feed tube 40 into an inlet tube 74 (FIG. 2) of theapplicator 20.

In connection with extruding many forms of adhesives and sealers,particularly expandable adhesives, it is important to help keepprocessing temperatures below the activation temperature of thematerial. One way to do this is to control shear, so that theapplication of pressure to the material will not result in heating thematerial. The use of a precisely controlled motor (such as an hydraulicmotor) to drive the extruder helps allow precise control over thecompression characteristics of the extruder. A hydraulic motor 72, forinstance, provides a large amount of torque and possesses a fastresponse curve, thus allowing the extrusion to be started and stoppedvery quickly. This control characteristic is advantageous especially inconnection with extruding flowable materials in applications havingstrict tolerance limits.

One preferred apparatus for applying the flowable materials is at leastpartially automatically controlled, although a combination of manual andautomatic control is contemplated and in some circumstances may bedesirable. Preferably, a control system sends computerized commandstelling the applicator when to supply the flowable material to thecomponents such that the material is properly applied to appropriatepredetermined surfaces of the components. In the preferred embodimentshown in FIG. 3, virtually all functions of the extruder 20 andassociated robot 22 can be controlled by a PLC 60 (programmable logiccontroller), although other computerized systems and computer softwaredriven systems can be used in the present invention. Electrical controlsignals are delivered from the PLC 60 via line 66 to the hydraulic pump44, via one line 64 to various servo motors on the robot 22 and viaother lines 62 to three separate heating elements 114, 116 and 118surrounding the middle and lower reaches of a barrel (e.g., cylindricalbarrel) 86 of the extruder 20.

Since the extruder is required to modulate the extrusion rate(throughput), the screw is subjected to a highly variable torque andtherefore is subject to variable reaction forces. A preferred screwbearing assembly therefore comprises at least two thrust bearings (orthe like), 514, 516 FIG. 15, acting in opposite directions. It iscontemplated that the present invention also incorporates a process forthe use of repeatable and predictable amounts of materials so that theextruder essentially functions as a quasi volumetric pump which cantightly control the rotation angles of the screw. A closed-loopservo-control system can be used to achieve, control, and operate theposition of the screw and may comprise an hydraulic system (which mayfurther include a servo valve) or an electric servomotor. It iscontemplated that the hydraulic system is desirable in applicationswhere weight is a prime factor while for stationary systems, theelectric system may be the prime choice.

It may be desirable to heat the surface of the components to receive theflowable material prior to applying flowable material to the surface.For example, some processes of the present invention include steps ofheating the surfaces for cleaning (e.g., driving off a contaminant), forenhancing the adhesion, for thermally expanding the component orcombination thereof. The surface may be heated by radiation, conduction,convection or combination thereof, using a heater such as an oven orfurnace into which the components are inserted and removed, or arepassed through, by a bath, by a light source (e.g., a laser, a lamp, orotherwise), a flame, an inductor or some other suitable heater. Theheater may be provided as part of the apparatus for applying theflowable materials or separately, both of which are discussed below.

In the particular embodiment shown, an optional air blower 47 is mountedon the arm 30 of robot 20 delivers air through line 45 to anelectrically heated manifold 68 to which there is attached an outlet airnozzle 70. The manifold 68 and a temperature sensor 69 on the end ofnozzle 70 are connected to the PLC 60 via lines 71 and 73, respectively.The manifold 68 is pivotably mounted on a rod 83 which is longitudinallyadjustable within a threaded mounting flange 85 which is secured to ahub 110 forming part of the extruder 20. By this manner of mounting, theend of the nozzle 70 may be adjusted so as to direct warm air at adesired temperature onto the substrate in close proximity to the pointwhere an extruded bead of material exits an extrusion die 126 and isdeposited onto the components.

For the hydraulic motor 72 shown in FIG. 2 a pair of threaded fluidports 95, 97, are adapted to be coupled with the hydraulic lines 42. Thehydraulic motor 72 is mounted through a spacer 96 and adapter ring 94 toa cylindrical hub 110. The adapter ring 94 surrounds the output shaft102 and is received within a cylindrical depreciation within the hub110. A rotatable output shaft 102 of the motor 72 extends through thehub 96 and into an opening in the hub 110 where it is secured via a key100 to the upper reaches of feed screw 88. A sensor 98, such as a tachsensor, is mounted on the spacer 96 to sense the rotation of the shaft102, including the rotational speed of the shaft 102. The upper end ofthe feed screw 88 is journaled for rotation within the hub by means of athrust bearing comprising a pair of bearing races 104, 108 and rollerbearings 106.

The upper end of the cylindrical barrel 86 includes a cylindrical flange101 secured by bolts to a circumferentially extending shoulder of thehub 110. A lateral opening 112 in the sidewall of barrel 86 providespressure relief. An inlet opening 90 in the barrel 86 allows theintroduction of solid material pellets 105 into the interior of thebarrel 86, at the upper end of the feed screw 88. The inlet feed tube 74forms a slight dog leg feed path into the opening 90 which may,depending upon the nature of the pellets 105 and the attitude of theextruder 20, become jammed somewhat, from time to time, therebypotentially interrupting constant flow to the feed screw 88. Toeliminate this problem, a swivel feed tube connection has been providedfor coupling the feed tube 40 to the inlet tube 74. This connectioncomprises an inner, tubular sleeve 92 which extends down into the inlettube 74 and is secured to the feed tube 40. The inner sleeve 92 includesa circumferential flange 107 which rotatably bears upon a mating flange109 on the upper end of inlet tube 74. Flanges 107 and 109 are receivedwithin a groove in a collar 84 which is secured to sleeve 92 and has aportion surrounding inlet tube 74. From the description of the foregoinginner connection, it may thus be appreciated that the inner sleeve 92,collar 84 and feed tube 40 rotate independently of the inlet tube 74. Bythis arrangement, in the event that the pellets 105 of material jam nearthe bottom of the inlet tube 74, the rotational movement of the feedtube 40, and thus the inner sleeve 92 tends to dislodge the pellets sothat they flow freely into the inlet opening 90 so as to smoothly feedinto the screw 88. In alternative embodiments, a gas such as air may beblown into the feed tube at regular intervals to assist the flow anddispensation of the pellets and otherwise avoid jams of the pellets.Also, it may be appreciated that the extruder may be moved andmanipulated during the extrusion process through many degrees of motionwithout stressing or otherwise interfering with proper flow of pelletsthrough the feed tube 40, since the feed tube 40 rotates freely upon theextruder 20.

It may be desirable to raise, lower or maintain the temperature of theflowable materials such that the materials flow properly into, throughand out of the applicator. More often than not, it is desirable to raisethe temperature of the flowable materials particularly when thematerials are brought to a flowable state by heating. The flowablematerials may be heated before entering the applicator, while in theapplicator or after leaving the applicator. Various heating mechanismsmay be used to heat the flowable material prior to, during, or after thematerials are within the applicator. Examples of heating elementsinclude wire wound rubber heaters, mounted heater subassemblies, coilwire heating elements, flexible heating elements, or the like.

As indicated earlier, in the preferred embodiment, the medial and lowerreaches of the barrel 86 have mounted therearound band shaped heatingelements 114 which are controlled by the PLC 60. The heating bands 114,116 and 118 surround the barrel 86 and are provided with temperaturesensors 113 to provide temperature feed back information to a display(not shown) and the PLC 60. The lower heating band 118 can be seen toreach virtually to the end of the barrel 86, adjacent the extrusionnozzle 120. The heating bands 114-118 function to melt the pellets 105into a flowable material which is fed by the screw action of feed screw88 to an accumulating chamber 122 and thence through a tapered feedpassage 124 within nozzle 120 to an extrusion die 126. Extrusion die 126possesses an extrusion opening therein which has a cross-sectionconforming to the desired shape of the extruded bead. The extrusion die126 is threadably received within in the nozzle 120 which in turn isthreadably received within a lower threaded opening in barrel 86,concentric with the central axis of feed screw 88. A pressure sensor 128secured within nozzle 120 delivers signals to the PLC 60 relating to thepressure of the flowable material as it enters the die 126.

In a preferred embodiment, the PLC operates the extruder using closedloop control on the rotation of the screw of the extruder. (i.e., thesensor tells the PLC how fast the extrudate is being emitted and thescrew of the extruder may be rotated slower or faster to realize aproper rate). In this manner, control over the rate of emission of theextrudate can be precisely controlled and the extruder can get to thedesired speed of emission in a very short period of time (e.g., lessthan a second).

In a highly preferred embodiment, the applicator uses closed loopcontrol based upon a metering system. In such a system, the output offlowable material from the extruder is experimentally related to thepositioning angle of the extruder and the rotational speed of theextruder screw. With reasonable amounts of experimentation the amountsof volumetric flowable material output for different rotational speedsof the extruder screw can be known to a reasonably high degree ofcertainty thereby permitting proper volumetric output of flowablematerial as long as the rotational speed of the extruder screw iscommesurate with such output. Thereafter, a desired profile may be inputto the PLC for a chosen component. Preferably, the profile relates thedesired amount of flowable material output over time, the desiredpositing angle of the extruder, or both to the desired rotational speedof the extruder screw for a chosen component. As the flowable materialis output, data regarding the angle of the extruder and the rotationalspeed of the extruder screw are monitored via sensors such as the sensor98 or other devices and the data can be sent to the PLC. In turn, thePLC commands the motor to either raise, lower or maintain the amount oftorque that the motor is applying to the extruder screw such that theoutput of flowable material or the rotational speed of the extruderscrew closely mirror the desired profile. In this manner, the extruderis used as a metering device. Since the output of flowable material isvery closely related to and predictable based upon screw rotationalspeed.

Depending upon the flowable material that is being applied, it may bedesirable to remove excess or stray material from the applicator betweeneach application or intermittently between applications to avoidinterference with flowable material output.

In exemplary embodiments, excess material may be removed from theapplicator by directing a gas such as air at the outlet of theapplicator. Alternatively, excess material may be removed manually bywiping the outlet with a cloth or other wiping material. Grinding orpolishing steps may also be employed. As shown in FIG. 1, a wiper may beprovided comprising a wiping wire 80 held between the ends of two arms78 which are mounted on the end of a rod 76. Preferably, the rod 76 isslidably adjustable within a holder 77 mounted on the table 38. In orderto wipe excess material from the end of the nozzle 126, the robot 22moves the extruder 20 such that the outer end of the die 126 passesacross the wire 80 which cuts off the excess material.

Alternatively or additionally, the applicator 20 may be programmed topull the flowable material within the applicator 20 after eachapplication such that excess material is removed. In the embodimentwherein the applicator is an extruder, the PLC may be programmed toreverse the turning direction of the extruder screw such that theflowable material is drawn back into the extruder 20 for a short periodof time or for a short distance after each application therebyminimizing the excess material on the end of the die 126 after eachapplication.

Attention is now directed to FIG. 8 which depicts, on a larger scale, analternate form of nozzle arrangement for the extruder 20, in which aplurality of extrusion dies 128, 130 and 132 are provided. The multipledies 128-132 may be positioned in the nozzle body 120 a at any desiredposition or angle, relative to each other, and may possess die openingswhich differ in their characteristics (size, cross-sectionalconfiguration, etc.). This permits on-line extrusion of differentlyconfigured beads without the need for changing dies or using multipleextruders. The bottom end of the feed passageway 124 delivers flowablematerial to the dies 128-132 via distribution channels 140, 142 and 144.In the embodiment shown, flow of the material is selectively controlledto the multiple dies 128-132 by means of valving, herein illustrated asball valves 138 which are operated by linkage rods 138 operated by anysuitable form of motors or drive mechanisms such as pneumatic cylinders136.

In alternative embodiments, various fastening mechanisms may be used toattach dies such as extrusion dies 128, 130 and 132 to an applicatorsuch as the extruder 20. For example, it is contemplated that thefastening mechanisms may include quick connect or quick changeattachment devices such as quick connect nut and bolt fastener,hydraulic quick connect fasteners, male/female quick connect fastenersor the like.

In other alternative embodiments, the apparatus for applying flowablematerials may be configured for coextruding a plurality of materials(e.g., plastic combinations, metal and plastic combinations, orotherwise). For example, more than one die may be secured to a singleapplicator or a single die may have more than one opening for emittingseparate beads of materials.

For certain embodiments of the present invention, it may be desirablefor flowable material to be applied to a substrate or component at onelocation, followed by transporting the component or substrate to asecond location for assembly to an article of manufacture. For example,in the automotive industry, an automotive supplier may desire to apply aflowable material to a substrate or component at its own facility thatis geographically remote from an assembly plant (e.g., an originalequipment automotive vehicle assembly line). Thereafter, the componentor substrate is typically shipped or otherwise transported to anautomotive assembly plant where it is assembled to a vehicle preferablyprior to painting of the vehicle. Alternatively, it may be desirable toapply flowable material to a component or substrate in the same locationthat the component or substrate is assembled to an article ofmanufacture.

Attention is now directed to FIGS. 4, 5 and 6, which depict the extruder20 adapted for use in an in-line extrusion application for automatedassembly of vehicles on a production line. Vehicle bodies 146 on amoving production line 154 pass by a sealant application stationcomprising the previously described extruder 20 mounted on the end of arobot 22. Under programmed control of the PLC 60 (FIG. 3) the extruder20 automatically extrudes a bead 152 of material into a channel 150formed in the roof surface 148 of each vehicle 146. By virtue of theprecise control of material flow afforded by the use of the motor 72,and the exceptionally light weight of the extruder 20 owing to itsconstruction which allows it to be placed on the end of a robotic arm, aprecisely configured bead of sealant may be introduced at the properlocation within the channel 150 around the entire periphery of the roofsurface 148, while the vehicle 146 moves down the assembly line.

According to preferred embodiments, apparatuses according to the presentinvention may be configured to place flowable materials upon componentsof vehicles within very tight tolerances. In a preferred embodiment,flowable materials may be placed within at least one centimeter of theirintended location, more preferably within three millimeters of theirintended location and even more preferably within one millimeter oftheir intended location.

As previously stated, it can be important for the sealant bead 152 toexit from the extruder 20 at the proper temperature, with proper flowcharacteristics and with a desired cross-sectional configuration for thesealant bead 152 to properly perform its function. These materialcharacteristics are particularly important in various applications, asfor example where sealant material is used which later expands aftercuring or after application of heat, to fill voids (e.g., cavities,gaps, seams or the like). Such applications may be applied to automotivevehicles components such as bulkheads, instrument panels, wheel wells,floor pans, door beams, hem flanges, vehicle beltline applications, doorsills, rockers, decklids, hoods, etc. Moreover these components may beformed of metal stampings, molded plastic, extruded plastic, machined orcast metal or the like.

As an example, FIG. 7 a depicts the roof surface 148 immediately after aroof panel 154 has been installed in overlying relationship on thevehicle 146; a slight gap forming a void is present between the roofpanel 154 and roof surface 148. FIG. 7 b shows the relationship of thesecomponents after the bead of sealant has been expanded through curingand/or the application of heat to fill the void between the body parts.The control overflow characteristics of the sealant material is achievedin a very precise manner, for several reasons. First, as stated before,the use of a hydraulic motor 72 results in the provision of a very highlevel of torque to the feed screw 88, yet the weight of the hydraulicmotor 72 is not so great as to preclude mounting the extruder 20 on arobot arm. The sensor 98 precisely senses the rotation of the feed screw88, and thus provides immediate feedback information which allows thePLC 60 to control the hydraulic motor 72 accordingly. Also, the heatingbands 114-118, along with temperature sensors 113 envelop the sealantmaterial to define separately controllable heating zones and control thefinal temperature quite precisely as the material exits the extrusiondie 126. The exact flow rate of sealant material exiting the die 126 isfurther controlled as result of the provision of the pressure sensor 128which provides feedback information to the PLC 60 relative to thepressure of the sealant material immediately before it is extruded,which in turn is directly related to flow rate or as a result of thesensor 98 monitoring rotational speed of the extruder screw, which canalso be related to flow rate. The unique rotatable connection of thefeed tube 40 to the extruder 20 also assures constant, controllable flowrate in that temporary interruption or diminution of material feed iseliminated. Finally, the provision of a flow of precisely directed hotair emanating from the heat nozzle 70 allows the substrate to bepre-heated, thereby better conditioning the extruded material to absorboils and the like from the substrate.

For some applications, alternate forms for feeding solid pellets of asealant material to the extruder 20 may be provided. For example, asshown in FIGS. 9 and 10, batch hopper 156 may be mounted on the extruder20 to supply material pellets, rather than the flexible feed tube 40discussed earlier. The batch hopper 156 gravity feeds pellets through anelbow tube 166 which is connected with the inlet tube 74. The size ofthe batch hopper 156 accommodates a single “batch” which is sufficientto apply sealant to a given part or for a specific job. In order toreplenish the batch hopper 156, the robot 22 swings the extruder 20 to aloading position, in which the hopper 156 is positioned beneath amaterial dispenser 158, with a discharge tube 160 of the dispenser 168extending down into the interior of the hopper 156, as best seen in FIG.10. A motor member 162 which may be electrical, hydraulic or pneumatic,controls a discharge valve diagrammatically indicated by the numeral 164in order to allow a single batch of material to be dispensed through thedischarge tube 160 into the hopper 156. After a batch of material hasbeen so discharged, the robot 22 lowers the extruder 20 into clearingrelationship to the dispenser 158 and discharge tube 160. As the hopper156 moves away in this manner, the remaining material within thedischarge tube 160, beneath the valve 164, flows down and into thehopper 156. In other alternatives, the applicator may be continuouslylocated below the supply of pellets (e.g., wherein the applicator isrelatively stationary) such that the supply of beads or pellets can becontinually replenished and the beads can continuously flow to theapplicator under gravitational forces.

In preferred embodiments, dissimilar pellets may be fed to an extruderto form a flowable material as a blend of materials. According to aparticularly preferred embodiment, one material may be introduced inpellet or other form into a first opening in the extruder and a secondmaterial may be introduced in pellet or other form into a second openingin the extruder. In this manner, a flowable material may be formed thatincludes layers of different materials that are “candy-striped” alongthe length of the flowable material when the material is applied to acomponent. Preferably, the openings through which the pellets ofdifferent material enter the applicator are generally opposite eachother to form the layers of flowable material. In this manner, variousmaterials such as more highly reactive material may be combined withother materials later in the process of forming the desired flowablematerial to prevent undesired or premature reaction between suchmaterials.

Attention is now directed to FIGS. 11 and 12, which depict an alternateform of the extruder of the present invention, generally indicated bythe numeral 180. The extruder 180 is similar or identical to thepreviously described extruder in terms of its component parts; onlythose parts that may be different than those previously described willbe discussed here. The extruder 180 is mounted for limited movementabout two orthogonal axes, at a stationery position along an assemblyline which includes a conveyor 168. Conveyor 168 moves parts such as themetal channel part 172 along a path guided by transversely spaced,stationary feed guides 170. Feed guides 170 precisely control thetraverse positioning of the part 172 as it passes by the extruder 180.

The extruder 180 is pivotably mounted on a pair of spaced apart mountingflanges 186 which are secured to a base 192. A pair of forwardlyextending arms 190 have one end connected to the structure supportingthe extruder 180, and the other end connected to the output shaft of ahydraulic or pneumatic cylinder 188 which functions to raise or lowerthe extrusion die 176. Counter weights, may be mounted on the oppositeend of the extruder 180, as required, to achieve proper balance. A batchtype hopper 178 is provided on the extruder 180 to supply pellets orother solid forms of sealant material. A hot air source (e.g., a blower)182 is mounted up-stream from the extrusion die 176 to apply hot air ata desired temperature via the exit nozzle 184 to preheat the part 172.Other heating mechanisms, such as those identified elsewhere herein mayalso be employed as desired.

A guide shoe 174 mounted on a guide arm 194 of the extruder 180 isadapted to be received within a groove or channel in the part 192 andfunctions to pivot the extruder 180 about an axis (e.g., a verticalaxis), depending upon the traverse position of the channel or groovewithin the part 172. In this manner, the shoe 174 acts as a cammingguide to precisely move and locate the extrusion die 176 relative to thepart channel so that the bead of sealant material is dispensed inprecise registration within the groove or channel within the part 172.

Quality Control

For quality control purposes, it may be desirable to track materials asthe materials are fed to the applicators. For instance, it may bedesirable to supply batches of material pellets in a particular order toassure that the proper materials are being applied to various componentsor to assure that the materials being used are less likely to be ageddeteriorated. As another example, it may be desirable to track the useof materials to monitor supply of the materials to determine when morematerials are needed.

Tracking of materials may be accomplished using labels, manual systems,automatic systems and the like. In one exemplary embodiment, and withreference to FIG. 13, a bar code system 300 may be employed. In FIG. 13,portions of an apparatus 302 for supplying flowable materials mayinclude bar code scanner. Preferably, the bar code scanners arepositioned upon portions of the apparatus 302 that initially receiveflowable materials in pellet form prior to processing. Exemplarypositions for such scanners may include positions adjacent supplycontainers 314 such as the bin 52 of FIG. 3 or positions adjacent thebatch hopper 178 of FIG. 11 such that the scanners may scan bar codesaffixed to the supply containers preferably prior to introduction ofmaterials from the containers 314 to the apparatus 302.

Preferably, the scanners are in signaling communication with acontroller 320 (e.g., a computer or other controller) for signaling tothe controller 320 the identification or bar code of any supplycontainer 314 that has been placed in position to feed material to theapparatus 302. The controller 320 may be programmed with data todetermine if the desired supply container 314 having the desired barcode has been positioned to supply the apparatus 302 at the desiredtime. Thus, if an undesired supply container 314 is positioned to supplymaterial, the controller 320 may signal a response. A variety ofresponses may be signaled such as an audible response (e.g., a horn,bell, tone, or siren), a visual response (e.g., a light, such as aflashing light), a combination thereof or another response. According toone preferred embodiment, the controller 320 is in communication withthe apparatus 302 such that the apparatus may be partially or fully shutdown if any undesired material is going to be fed to the apparatus 302.

Components and Application of Flowable Materials to the Components

The flowable materials disclosed herein may be applied to a surface of awide variety of components for several articles of manufacture. As usedherein a component may be one of several parts of an article ofmanufacture or a component may be the only part of an article ofmanufacture. The surface to which the flowable material is applied maybe substantially planar or may be contoured (e.g., curved, angled, arcedand the like). In a preferred embodiment, the surface at least partiallydefines a channel for receiving the flowable materials. In anotherpreferred embodiment, the surface is part of a component of anautomotive vehicle. In a highly preferred embodiment, the surface may bepart of any stamped metal component that is assembled within anautomotive vehicle structure.

It may be desirable to treat the surface of the component prior toapplying a flowable material to the surface. The surface may be cleansedof impurities such as dirt, grime, oil and the like prior to applicationof the flowable material, the surface may be heated prior to applicationof the flowable material, the surface may be coated prior to applicationof the flowable material or a combination of treatments may be performedon the surface. Particularly in the automotive industry, many componentssuch as stamped metal components and like contain excess impurities suchas oil, which are preferably removed prior to application of a flowablematerial. Such impurities may preferably be removed by exposing thesurfaces of compounds to energy from an energy source.

In one embodiment the surface is cleansed by exposing the surface to aplasma formed by a plasma generator. Plasma generators may generatevarious plasmas such as a non-thermal or non-equilibrium plasma or adielectric barrier plasma. The surface is exposed to the plasma and theplasma provides energy to any impurities located upon the surface. Inturn, the impurities are burned off, evaporated or otherwise removedfrom the surface such that the surface is more suitable for receiving aflowable material.

In an alternative embodiment, a laser or flash lamp may be used toexpose a surface of a component to energy beams or energy pulses.Preferably, the laser or flash lamp requires relatively low energy inputto produce energy pulses with relatively high peak power. One exemplarylaser is a Q-switched NdYag laser that can deliver relatively fast highpeak power pulses (e.g., pulses having pulse times of around 10nanoseconds, pulse powers up to and greater than 10 Watts and pulsewavelength of around 1 micron). Preferably, the exemplary laser candeliver such pulses with a frequency of about 100 Hz. It is believedthat the energy pulses form an unstable plasma on the surface of acomponent, wherein the plasma in an effort to stabilize generates ashockwave effect that blasts away grease, grime and other impuritiesfrom the surface of the component.

According to another embodiment, the surface of the component may beexposed to light from one or more heat lamps. Preferably, the heat lampsemit light toward the surface of the component wherein the light has awavelength typical of visible or near infrared light (e.g. around 750nanometers). The flash lamps remove impurities from the surfaces of thecomponents and the heat lamps may also heat the surfaces of thecomponents. In a highly preferred embodiment, the heat lamps directlight toward a surface of a stamped metal component of an automotivevehicle thereby evaporating the impurities (e.g., particularly oil) thatis often present upon the stamped metal components. Additionally in thehighly preferred embodiment the surface of the components are exposed tothe light from the heat lamps for a period of time that heats thesurfaces to a temperature substantially equivalent to the temperature atwhich flowable material is being applied to the component.

In still another alternative embodiment, a primer may be coated upon asurface of a component before a flowable material is applied to thesurface. The primer may be manually or automatically applied to thesurface of a component. Preferably, the primer is applied aftercleansing the surface of the component. Advantageously, the primerassists flowable materials in adhering to the surfaces of components. Inone highly preferred embodiment, the apparatus for applying the flowablematerials may be configured with a first nozzle or opening for applyingprimer and a second opening (e.g., of a die) for applying flowablematerials after the primer has been applied.

According to one preferred method of application, the flowable materialsmay be applied to the surface of a component without pre-heating thecomponent due to the type of flowable material being applied.Preferably, when applying the flowable material in this manner to thesurface of a component, the surface is pre-treated or cleansed using oneof the methods (e.g., plasma, primer, laser and the like) discussedabove. In one preferred embodiment, the flowable material or pellet oreven a plurality of pellets (in an uncured state) is generally dry orrelatively free of tack to the touch at room temperature.

In certain circumstances, the components may be moved relative to anapplicator such that the melt flowable materials emitted from theapplicator are properly positioned on the surfaces of the components. Asexamples, the component may be placed or mounted upon surface or othersupports and movement systems such as conveyor belts, robots, robotarms, carousels, turntables and the like for moving the componentsbeneath an applicator. These systems may move the components radiallyabout an axis, along a contoured path, along one or more lines orotherwise. Moreover, these systems may move independently or dependentlyrelative to a robot arm, which may move the applicator and these systemsmay have a same or different controller from the robot arm. Thecomponents may be moved relative to the flowable materials eitherfaster, slower or at substantially the same rate that the flowablematerials are emitted from an applicator. The flowable materials may beapplied to the components along almost any predetermined path.

Additionally, the flowable materials may be applied to the components ina variety of shapes. As an example, the flowable materials are appliedas beads through a die and assume the shape of an opening of the die. Byusing different dies, different shapes may be achieved. Moreoverflowable materials may be applied as a single continuous bead or as aplurality of spaced beads. The beads also may vary in size as desired.For example, cross-sectional areas of the beads may range from about 1mm² up to about 1000 mm² and more preferably from about 10 mm² to about500 mm² and still more preferably from about 100 mm² to about 300 mm².

According to one embodiment, it may be desirable for the flowablematerials to maintain certain chemical or physical properties, referredto herein as pre-assembly properties, for relatively large intervals oftime between application of the flowable materials to a component andassembly of the component to an article of manufacture. After assembly,however, it may be desirable for the flowable materials to exhibit otherphysical properties referred to herein as post-assembly properties.Flowable materials are provided according to the present inventionwherein the materials applied to the components exhibit properties suchas non-tackiness and the like, shortly after they are initially appliedto the components. In this manner the flowable materials may be appliedto the components in a condition suitable for transport (i.e., thecomponents can be placed adjacent or in contact with each other or othercomponents without the flowable materials adhering or otherwiseattaching to adjacent components). Thereafter, the flowable materialscan be triggered by heat, chemicals or other stimulus to change thechemical or physical properties of the flowable materials during orafter the time that the components upon which the flowable materialsreside are assembled within an article of manufacture. The chemical orphysical properties after triggering may include adhesivity, expansionand the like.

It is contemplated that the flowable material 20 is applied in avisco-elastic state which can easily and uniformly be applied to anexterior surface of the components in a relatively clean manner where ithardens and bonds. Once the material is applied to a component in adesired shape and pattern, the material cools at the ambient temperaturefound in a manufacturing facility which allows the material to return toits original solid or dry chemical state thereby bonding and adheringthe material to the external surface of the component. The component isthen integrated into an article of manufacture such as an automotivevehicle for application of heat such as from the e-coat process as wellas other paint operation cycles commonly found in an automotivemanufacturing facility. The material is allowed to expand, therebychemically cross-linking the material on the external surfaces ofadjacent components of the article of manufacture.

According to one highly preferred embodiment, the flowable material is aplastic adhesive that is non-tacky below a first temperature of, forexample, around 40 degrees Celsius but exhibits tackiness when heatedabove the first temperature and exhibits an even higher degree oftackiness at a second higher temperature, which is around thosetemperature exhibited by a typical e-coat process as discussed above.Thus, the plastic adhesive can be applied to the components attemperatures between 40 degrees Celsius and 180 degrees Celsius and theadhesive will adhere to the components adequately for the adhesive to betransported but without any high degree of deformation of the flowablematerial. Preferably, the flowable material is still substantially inits green or non-activated/non-cured state. Thereafter, the adhesive maybe cooled or partially cured to temperatures below around 40 degreessuch that the component and the adhesive may be transported without theadhesive adhering to other objects, which it may come into contact with.Then, the component may be assembled within an article of manufactureand the temperature of the adhesive may be elevated to the secondtemperature so that the component is adhesively secured as a componentof the article of manufacture once the adhesive is again cooled orfinally cured. Such an adhesive provides an advantage over otheradhesives since it doesn't typically sag, run, wash away or getdisplaced during processing and handling.

It has been found that structural attachment may be best achieved whenthe material is selected from the group consisting of productdesignations L-5204, L-5205, L-5206, L-5207, L-5208, L-5209, L-5214,L-5222 and L-8000 sold by L&L Products, Inc. of Romeo, Mich. Forsemi-structural attachments, best results were achieved when thematerial is selected from the group consisting of product designationsL-4100, L-4200, L-4000, L-2100, L-1066, L-2106, and L-2108 sold by L&LProducts, Inc. of Romeo, Mich.

There are many components suitable for receiving flowable materialsaccording to the present invention. The flowable materials may beapplied to metal surfaces of components, coated or uncoated, painted orunpainted, welded or unwelded. In preferred embodiments, the flowablematerials are applied to components of automotive vehicles such as doorbeams, closure panels such as trunk lids or hood lids, roof bows, fuelfiller doors, exterior trim, vehicle A-pillars. The flowable materialsmay also be applied in an automotive vehicle roof ditch, upon emblems orwithin a water management trough surrounding the trunk space of avehicle. Additionally, the flowable materials may be applied tosuspension components, hangers, brackets and the like for systems suchas exhaust systems. Other components include hem flanges, emblems andthe like. Moreover, the flowable materials may be applied to componentsin need of dampening, sealing or corrosion protection.

The materials may be applied to fill seal or other occupy various holesor openings within vehicles such as rat holes, space between dissimilarmetals, notches and the like. According to preferred embodiments, thematerial may extend across holes, openings or other gaps withoutsagging.

According to one embodiment, it is contemplated that flowable materialsmay be applied to various portions or regions of substantially awhole-body side panel. With reference to FIG. 14, there is illustrated asystem 500 for applying flowable materials to whole-body side panels 504for automotive vehicles. The system 500 includes a robot 508 for movingand otherwise manipulating the side panels 504. The system 500 alsoincludes an apparatus 512 for applying melt-flowable materials. Theapparatus 512 includes an applicator (e.g., an extruder) as discussedabove. According to one embodiment, the robot 508 has the capability tosupport the panels 504 and move the panels 504 relative to theapparatus. Preferably, the robot 508 moves at least one of the panels504 below the applicator of the apparatus 512 according to apredetermined pattern. As the panel 504 is moved, the applicatorpreferably emit flowable materials at predetermined times such that theflowable materials are applied to the panel 504 at predeterminedlocations.

To the extent not expressly addressed in the above, it will beappreciated from the claims that follow that any of a number ofdifferent combinations of the specifically recited steps or componentscan be employed and are contemplated by the present invention.

It is recognized, of course, that those skilled in the art may makevarious modifications or additions to the preferred embodiments chosento illustrate the invention without departing from the spirit and scopeof the present contributions of the art. Accordingly, it is to beunderstood that the protection sought and to be afforded hereby shouldbe deemed to extend to the subject matter claimed and all equivalentsthereof fairly within the scope of the invention.

1. A method for applying a flowable material to a component of anarticle of manufacture, the method comprising: providing a first surfaceof the component; and extruding the flowable material upon the firstsurface in a slightly flowable state, using an extruder including anectruder screw such that the flowable material wets and adheres to thefirst surface wherein: i) a controller employs closed loop control tocontrol output of flowable material based upon a metering system thatrelates screw rotational speed of the extruder and positioning angle ofthe extruder to the output; ii) the output of the flowable material fromthe extruder has been experimentally related to the positioning angle ofthe extruder and the rotational speed of the extruder screw for creatingan output profile that is programmed to the controller; iii) the profilerelates the desired amount of flowable material output over time and thedesired positioning angle of the extruder, to the desired rotationalspeed of the extruder screw for a chosen component; iv) as the flowablematerial is output, data regarding the angle of the extruder and therotational speed of the extruder screw are monitored via sensors; and v)an amount of torque applied to the extruder screw is either raised,lowered or maintained such that the output of flowable material or therotational speed of the extruder screw closely mirrors the outputprofile.
 2. A method as in claim 1 wherein the first surface includes atleast one contaminant material disposed thereon and the method furthercomprises treating the first surface of the component for removing theat least one contaminant material therefrom and the step of treating thefirst surface of the component includes applying a primer to the firstsurface, washing the first surface or exposing the surface of thecomponent to energy from an energy source for removing the at least onecontaminant material from the first surface and wherein the flowablematerial includes a blowing agent that foams the flowable material at anelevated temperature experienced during an automotive coating process.3. A method as in claim 1 further comprising: providing the extruder asa substantially stationary extruder in communication with the supply ofthe flowable material; providing a robot adjacent the extruder, therobot capable of attaching to and moving a whole-body side panel of anautomotive vehicle in a plurality of directions relative to thestationary extruder; moving the whole-body side panel of the automotivevehicle according to a predetermined pattern below the extruder duringapplication of the flowable material to the component.
 4. A method as inclaim 1 wherein the step of extruding the flowable material to the firstsurface occurs without pre-heating the first surface.
 5. A method as inclaim 1 wherein the flowable material is an epoxy based flowablematerial and the flowable material includes an ingredient selected froma solubilizing agent, a low compatibility component, a polar ingredientor an ingredient modified with an adhesion promoter and wherein theflowable material has a base resin with a narrow molecular weightdistribution.
 6. A method as in claim 1 further comprising assemblingthe component to the article of manufacture wherein the article ofmanufacture is an automotive vehicle wherein the component is a part ofthe automotive vehicle selected from a door beam, a closure panel, atrunk lid, a hood lid, a roof bow, a fuel filler door, exterior trim ora vehicle pillar.
 7. A method for applying a flowable material to acomponent of an article of manufacture, the method comprising: providinga first surface of the component; extruding the flowable material uponthe first surface in a slightly flowable state, using an extruderincluding an ectruder screw such that the flowable material wets andadheres to the first surface wherein a controller employs closed loopcontrol to control output of flowable material based upon a meteringsystem that relates screw rotational speed of the extruder screw to theoutput; heating the surface of the component prior to applying theflowable material to the surface wherein the step of heating the surfaceincludes exposing the surface to a lamp, exposing the surface to ablower, exposing the surface to a flame or combinations thereof;transporting the component along with a plurality of other componentswherein the flowable material is substantially tack-free at temperaturesnear room temperature; and assembling the component to the article ofmanufacture wherein the article of manufacture is an automotive vehicle;wherein the step of extruding the flowable material includes extrudingthe flowable material with an automated apparatus, the automatedapparatus including: i) a supply of the flowable material, the flowablematerial being provided as pellets in a container; ii) an extruder incommunication with the supply of flowable material for receiving thepellets, the extruder capable of intermixing the pellets of flowablematerial into a viscoelastic state and dispensing the flowable material,the extruder including the rotatable screw for dispensing the flowablematerial; and iii) a system for moving the extruder or the componentduring dispensing of the flowable material; wherein the controller is incommunication with the extruder and the system and wherein the extruderincludes a heating element for heating the flowable material to adesired temperature and wherein the component is formed of a metalselected from steel, aluminum, or stamped metal and wherein thecontroller is a programmable logic controller in communication with theextruder, the programmable logic controller programmed with a profilethat relates an output rate of flowable material to a position angle ofthe extruder and a rotational speed of the extruder screw and whereinthe programmable logic controller employs closed loop control inconjunction with the profile to set the output rate at a desired level.8. A method as in claim 7 wherein the extruder includes a nozzlearrangement including an extrusion die through which material isextruded from the extruder to the component and wherein the extrusiondie is attached to the extruder with a quick change attachment deviceselected from a quick nut and bolt fastener, a hydraulic quick connectfastener or a male/female quick connect fastener and further wherein theextruder die includes a plurality of openings for emitting a pluralityof beads of flowable material.
 9. A method as in claim 7 wherein theextruder is configured to dispense the flowable material upon thecomponent within a tolerance of less than 3 millimeters upon a surfaceof the component.
 10. A method as in claim 7 wherein the system includesa robot arm, a conveyor or a carousel for moving the component and theapparatus includes a source of vacuum pressure for moving pellets fromthe container to the extruder.
 11. A method for applying a flowablematerial to a component of an article of manufacture, the methodcomprising: providing a first surface of the component; and extrudingthe flowable material upon the first surface in a slightly flowablestate such, using an extruder including an extruder screw that theflowable material wets and adheres to the first surface wherein: i. acontroller employs closed loop control to control output of flowablematerial based upon a metering system that relates screw rotationalspeed of the extruder screw to the output; and ii. the controller isprogrammed to reverse a direction of rotation of the extruder screw forretracting the flowable material a short distance after an applicationof the flowable material to the component; and iii. a screw bearingassembly is associated with the extruder, the assembly having a firstthrust bearing and a second thrust bearing, wherein the first and secondthrust bearings act in opposite directions.
 12. A method as in claim 11further comprising: transporting the component along with a plurality ofother components wherein the flowable material is substantiallytack-free at temperatures near room temperature; and assembling thecomponent to the article of manufacture wherein the article ofmanufacture is an automotive vehicle.
 13. A method as in claim 12wherein the flowable material is an epoxy based flowable material andthe flowable material includes an ingredient selected from asolubilizing agent, a low compatibility component, a polar ingredient oran ingredient modified with an adhesion promoter and wherein theflowable material has a base resin with a narrow molecular weightdistribution and wherein the flowable material includes a blowing agentthat foams the flowable material at an elevated temperature experiencedduring an automotive coating process.
 14. A method as in claim 13wherein the step of extruding the flowable material includes extrudingthe flowable material with an automated apparatus, the automatedapparatus including: i) a supply of the flowable material, the flowablematerial being provided as pellets in a container; ii) an extruder incommunication with the supply of flowable material for receiving thepellets, the extruder capable of intermixing the pellets of flowablematerial into a viscoelastic state and dispensing the flowable material,the extruder including the rotatable screw for dispensing the flowablematerial; and iii) a system for moving the extruder or the componentduring dispensing of the flowable material; wherein the controller is incommunication with the extruder and the system and wherein the extruderincludes a heating element for heating the flowable material to adesired temperature.
 15. A method as in claim 14 wherein the componentis formed of a metal selected from steel, aluminum, or stamped metal.16. A method as in claim 11 wherein the output of the flowable materialfrom the extruder has been experimentally related to the positioningangle of the extruder and the rotational speed of the extruder screw forcreating an output profile that is programmed to the controller andwherein, as the flowable material is output, an amount of torque appliedto the extruder screw is either raised, lowered or maintained such thatthe output of flowable material or the rotational speed of the extruderscrew closely mirrors the output profile.
 17. A method for applying aflowable material to a component of an article of manufacture, themethod comprising: providing a first surface of the component: andextruding the flowable material upon the first surface in a slightlyflowable state, using an extruder including an extruder screw such thatthe flowable material wets and adheres to the first surface wherein: i.a controller employs closed loop control to control output of flowablematerial based upon a metering system that relates screw rotationalspeed of the extruder screw to the output; and ii. the controller isprogrammed to reverse a direction of rotation of the extruder screw forretracting the flowable material a short distance after an applicationof the flowable material to the component: wherein the output of theflowable material from the extruder has been experimentally related tothe positioning angle of the extruder and the rotational speed of theextruder screw for creating an output profile that is programmed to thecontroller and wherein, as the flowable material is output, an amount oftorque applied to the extruder screw is either raised, lowered ormaintained such that the output of flowable material or the rotationalspeed of the extruder screw closely mirrors the output profile.